1. Field of the Invention
The invention relates to gas separator/coalescer filter elements and in particular gas separator/coalescer filter elements in multi-stage vessels.
2. Description of Related Art
Gas filter elements for separating solids and liquids from contaminated gas streams are well known, as are gas filter elements for coalescing entrained liquids from a gas stream. Often these types gas filters are installed in multi-stage vessels, which are in turn installed in a gas pipeline, to perform these filtering functions. For example, U.S. Pat. No. 3,888,644 issued to Holland et al. discloses an apparatus with multiple compartments. In Holland, one compartment contains filter elements for separating solids and another compartment contains different filter elements for coalescing liquids entrained in the gas stream. The same is true for U.S. Pat. No. 4,297,116 issued to Cusick. Although these and other devices are capable of filtering solids and coalescing entrained liquids from a gas stream, they require completely different types of filter elements to perform the separating and coalescing functions. This adds to the costs of the devices and makes them difficult to maintain. There is a need for an apparatus with gas separator/coalescer filter elements that only requires a single type of filter element to perform separation of solids, filtering of liquids, and coalescing of liquids.